Solar energy collection

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35 a 48 SR

United States yX * 550 "mill 4-

Stark

(54. solar energy collection

76) inventor: Virgil Stark, 936 Fifth Ave., New

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683,266 1928 Shi 126/271 SS 22 Ety was a saw as w a 126/271 1951,403 3/1934 Goddard. ... 1227 2,920,710 1/1960 Howard ............................... 126/270 3,250,269 5/1966 Sherock ............................... 126/271 3,738,734 6/1973 Tait et al.. ... 350/179 3. 8, E. Matt - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - E,2. 33. %27: Ele C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126/271

4,069,812 1/1978 O'Neill ................................. 350/211 Primary Examiner-Samuel Scott

Assistant Examiner-Larry Jones

Attorney, Agent, or Firm-Kenyon & Kenyon

Apparatus and methods for concentrating and collect ing solar energy and for lowering the cost and increas ing the efficiency of solar energy systems are disclosed.

Solar energy is concentrated by economical refringent.

lenses or lens systems including fluid lenses and/or

Fresnel-type lenses. The lenses concentrate the solar energy preferably along lines in continuous linear foci or in discrete foci at an elongated collector comprising one or more fluid-carrying conduits and one or more fluids therein. In one embodiment, a plurality of photo voltaic cells are located in or on the collector along the linear foci or at the discrete foci and operate at in creased efficiency with heat being removed by the col lector. Heating at the photoelectric cells is reduced by utilizing a fluid lens in which the lens fluid and lens plates absorb heat-producing infrared rays which other wise would be converted to heat at the cells while per mitting the electricity-producing luminous rays to pass to the cells with little absorption by the lens fluid and plates. A first fluid in the collector is heated by the concentrated solar energy and in a disclosed embodi ment is used to heat a second fluid contiguous to the first fluid, the first fluid having a boiling point exceeding that of the second fluid. The first fluid is carried in an inner conduit while the second fluid is carried by an outer conduit which encloses the inner conduit and first fluid. Thus, the two fluids can be heated to different temperatures by a single concentrating system and used for different purposes. Energy is stored using two fluids of different boiling points. Also disclosed are methods and fixed and portable apparatus for distilling liquids including water containing salt or other substances by evaporation of the water and condensation of the water vapor wherein preferably the heat of condensation is recovered and heat in the condensate and brine is also preferably recovered. The invention also provides for assemblies of individual systems and subsystems to form larger and/or composite systems.

19 Claims, 22 Drawing Figures

Drawings

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exchanging manner with the panels. It is also known to

SOLAR ENERGY COLLECTION improve the efficiency of these systems by placing one

Cross-reference to related

or more glass plates above the panels to produce a

Applications

greenhose effect for reducing heat losses. However, the efficiency of these panel systems is low, from about

Part of the subject matter of this application is com 30% to about 40%, and they require large spaces result mon to application Ser. No. 746,065 filed on Nov. 30, ing in large heat losses, and they also require a high 1976 of which I am assignee, and co-inventor of the capital investment. The use of Fresnel-type lenses and invention described and claimed therein. fluid lenses is known in the art for focusing solar energy.

BACKGROUND OF THE INVENTION See, for example, U.S. Pat. Nos. 3,915,148; 3,125,091;

1. Field of the Invention nese Pat. No. 28-2130, and Australian Pat. No. 131,069. The present invention relates to methods and appara However, none of the known systems is capable of tus for concentrating and collecting solar energy for 15 converting and storing solar energy efficiently and none many uses including the conversion thereof to heat energy and/or electrical energy to be used for many can produce heat at an economical capital investment purposes. The present invention also relates to the stor other that such the use of solar energy is competitive with forms of energy. The prior art also does not dis age and use of heat energy during hours without sun close obtaining shine or with reduced sunshine. The present invention dred degrees C.temperatures in the order of a few hun while also obtaining at the same time further relates to the treatment of liquids including 20 lower temperatures usable for home heating and water water containing salt and/or other substances using fixed and portable apparatus and methods according to heating or other purposes. Nor is there in the prior art a system which is capable of storing heat energy from the invention. More particularly, the invention relates solar energy during periods of interrupted sunshine for to methods and apparatus using fluid and/or Fresnel any length of time and which also is capable of provid concentrating lenses and lens systems and elongated 25 collectors comprising at least one fluid-carrying conduit ing different temperatures simultaneously and also uti located at the foci of the lenses. lizing the luminous and utilizing or dispersing the heat 2. Description of the Prior Art produced by the infrared rays of the sun. The energy emitted by the sun corresponds to a high With respect to electrical generation, it is known that temperature in the order of 6000 C., and is emitted in 30 concentrating the solar energy at a photovoltaic cell the form of radiation which arrives at the earth with a will increase the electrical output of cell; however, wavelength distribution comprising about 3% ultravio there is the disadvantage that the increased heat in the let rays, 42% visible light rays, and about 55% infrared photovoltaic cell resulting from the concentration will rays. It is well known that surfaces exposed to the sun also limit the cell output. Known photovoltaic devices collect at least to some degree the solar radiation and 35 produce a maximum of about one watt per hour per cell. that the absorption of this radiation results in a heating Assuming a cost of $10 per photovoltaic cell, a system of the material constituting the surface. It is also known using non-concentrated solar energy to generate about that electricity can be produced by photoelectric de 1 kilowatt per hour requires a capital cost of at least vices exposed to the sun's rays. $10,000 which is not competitive for normal uses. There have been many attempts in the past to collect With respect to solar stills, known stills used for dis and utilize pollution-free and essentially nonconsumable tillation of seawater have low efficiencies and the cost solar energy to meet many energy needs. Much atten of heating the water is high as the least amount of heat tion has been directed to the conversion and utilization required to vaporize the water is not recovered from of solar energy in the past few years because of the condensation but rather is lost. realization that fossil fuels are exhaustible and that a 45

In accordance burning of these fuels produces pollution. Solar energy backs and disadvantages with the invention the prior art draw is inexhaustible and available above the clouds at an are substantially overcome and average energy level of approximately 1350 watts per additional advantages realized.

horizontal square meter. A percentage of this energy, SUMMARY OF THE INVENTION depending on atmospheric and weather conditions, 50 The present invention relates to methods and appara dust, pollution, etc., is available at the surface of the earth during periods of sunshine which vary up to about tus for concentrating, collecting, storing and utilizing solar energy and for lowering the cost and increasing 4000 hours per year depending on location. Even more the efficiency of solar energy systems. Refringent lens recently, the shortage of fossil fuels particularly oil and natural gas and the high cost thereof have sparked new 55 means concentrate the solar energy along a length at attempts to harness the energy of the sun. Heretofore, elongated collector means containing at least one fluid however, fuels were a less expensive source of energy therein. The lens means comprise economical fluid and than solar energy and the same problem of high capital /or Fresnel lenses and lens systems which focus the cost and the cyclic nature of the sun requiring storage solar energy substantially along the length at the collec capability have heretofore not been satisfactorily tor along substantially continuous lines or in lines of solved. For example, refringent lens focusing systems, substantially discrete points. Means are preferably pro most using reflecting collectors, have heretofore been vided to maintain the focus lines or discrete foci within used but are uneconomical and impractical because of conduit means comprising the elongated collector the high cost involved. A conventional system for ob means regardless of the seasonal and preferably also the taining lower temperatures up to about 80 C. consists 65 hourly (daily) location of the sun and/or means are of dark-colored panels absorbing the solar radiation and provided for seasonally and preferably also hourly means for removing the heat from the panels such as a (daily) tracking the sun. Thus, then at least one fluid in fluid system circulating a heat-carrying fluid in a heat the elongated collector means may be efficiently heated 13 to high temperatures in order of a few hundred degrees solar energy and high efficiency are possible. Means C. " . .. . may be provided to completely enclose the apparatus The fluid lenses comprise upper and lower solar en ‘while permitting movement of the lens means and col ergy transmitting plates which are advantageously sepa lector means to track the sun seasonally or also hourly. rate plates installed in frame means in a fluid-tight man Still further in accordance with the invention, both ner, or the fluid lenses including the plates may be the infrared and luminous rays of the sun may be sinul formed by gluing, welding, extruding, or being blown taneously or individually utilized. Photoelectric cells, in a manner similar to that for glass or plastic bottles. specifically, photovoltaic cells, are disposed at the col The enclosure in the lens containing the fluid may ad lector means such that the iuminous rays are concen vantageously be communicated with the collector O trated thereat for maximum electrical energy produc means to enhance performance. The fluid within the tion while the heat generated by the concentration of lenses preferably has a high index of refraction. The lens the infrared rays is removed by one or more fluids in the fluid and the distance between the lens plates may be collector means whose flow rates and volumes may be chosen to absorb varying amounts of infrared solar Iregulated. According to the invention, heating at the energy passing through the fluid. For example, more 15 photovoltaic cells is reduced by utilizing a fluid lens in infrared solar energy will be absorbed using, for exam which the lens fluid and lens plates absorb heat-produc ple, water as the lens fluid and less will be absorbed ing infrared rays which otherwise would be converted using a suitable transparent and colorless chemical to heat at the lens focus at the cells while permitting product having a high index of refraction. The heat electricity-producing luminous rays to pass to the cells absorbed by the lens fluid may be recovered and used to 20 with little absorption by the lens fluid and plates. preheat or heat fluid in the collector means or for other Concentration of solar energy may be increased by purposes. An antifreeze product may be added to the using several concentrators arranged to have a common lens fluid to prevent freezing of the lens fluid when it is focus. In one embodiment described for producing elec used in certain locations. It may be advantageous to tricity, this is achieved by eignpioying a central fluid (or absorb infrared radiation in the lens fluid where it is not 25 Fresnel) lens concentrating the solar energy in a focus desired to produce heat from the solar energy at the lens located at the photovoltaic cells and a piurality of Fres focus such as in certain instances when focusing the nel lenses located adjacent the central lens each pro solar rays on photovoltaic cells to produce electricity. vided with engravings thereon angled to direct solar The elongated collector means preferably comprises energy to the focus of the central lens. Heating of the a plurality of fluids, adjacent ones of which are contigu 30 photovoltaic cells is reduced by utilizing a central fluid ous. The fluids are preferably isolated and disposed in lens to absorb infrared energy and by placing the photo adjacent conduits and the fluids preferably differ and voltaic cells in collector means to remove heat there have varying boiling points. The theoretical focus or from produced by the infrared energy thereat. This foci of the lens means are preferably on the surface of or arrangement permits high concentration of solar energy within the higher or highest boiling point liquid. In a 35 with high conversion efficiency to electricity since disclosed embodiment, the elongated collector means heating of the celis is reduced. Thus, in accordance with comprises at least two conduits; one of the conduits the invention, the solar energy is concentrated by a containing a first fluid having a first boiling point is factor in the order of up to 100 so that one of the known located within a second conduit containing a second photovoltaic cells is able to produce up to 100 watts per fluid having a second boiling point. Preferably, the solar hour instead of, for example, 1 watt per hour during energy is concentrated at the inner liquid which has a periods of sunshine.

boiling point which exceeds that of the outer liquid. The The present invention further relates to distilation of conduits and fluids are solar energy transmitting or liquids in which water or other liquids may be distilled opaque or darkened depending on the location of the by locating the lens means focus in the water or liquid to lens means focus. By solar energy transmitting it is 45 be distilled, above which is positioned the lens means meant that the solar rays are substantially transmitted and a downwardly sloping substantially sinooth, prefer through the material. In this way, the fluids may be ably planar surface, whereby the liquid is evaporated heated to different temperatures and accordingly can be and condenses on the smooth surface which carries the utilized for different purposes, if desired. Regulation of condensed liquid to a collecting vessel positioned below the fluid flow rates and selection of conduit sizes and 50 the lower side thereof. Preferably, the planar surface is shapes assist in providing different temperatures which inclined at a slight angle with the horizontal, for exam may be utilized for different purposes. Arrangement of ple about 15, and is cooled to enhance condensation multiple conduits carrying multiple fluids can provide thereof. It is preferred that the lens means for the water energy for many different uses including vapor and distilling apparatus comprise a fluid lens which includes super-heated vapor for mechanical devices and expan 55 and preferably cools said smooth surface. In some em sion means including turbines, motors and engines; ad bodiments, conduit means are located in the liquid to be vantageously, the lower boiling point fluid has a low distilled. It is preferred that the fluid forming part of the latent heat of vaporization and is useful for this purpose. fluid lens is circulated within the conduit means where Additionally, heat is stored in the higher boiling point one is employed to advantageously utilize the latent fluid permitting its temperature to rise during periods of 60 heat released by the vapor, condensing on said snooth sunshine to a temperature substantially higher than that surface and transferred to the liquid to be distilled. It is of the lower boiling fluid which may be used as a work preferred that the lens fluid be the same liquid as the one ing fluid. Heat is removed from the higher boiling tem being distilled, salt water for example, and be circulated perature fluid by, for example, circulating the lower in the vessel containing the liquid to be distilled to heat boiling point fluid past the higher boiling point fluid. 65 or preheat the liquid in the vessel. In a disclosed en The invention also provides for the union of individ bodiment, distillation apparatus includes both fluid and ual systems and subsystems to form larger and compos Fresnel lenses in which the fluid lens is fixed and the ite systems. Thus, a high degree of concentration of Fresnel lens is, if desired, movable. The heat released by 14 the condensing liquid on said smooth lens means surface during periods without sunshine to continue the distilla is not lost and returned to the system in the conduit tion. The lens fluids for both sets of lenses recuperate means in the vessel containing liquid to be distilled, or heat absorbed by the lens fluid as described hereinbe elsewhere, and/or the heat absorbed and recuperated fore. The use of the different fluid lenses increases pro by the lens fluid may be used to preheat or heat the duction of distilled water and increases the efficiency of incoming liquid to be distilled in the distillation appara the system. According to one embodiment, the lens or tus or used for other purposes such as producing elec lens system focus is located in the water to be distilled tricity by superheating suitable low boiling temperature such that the location of the focus remains in the water fluids and expanding them in expansion means such as to be distilled with the changing location of the sun. turbines and engines, thereby increasing substantially 10 This eliminates the need for means to move the lens or the efficiency of the system. Additionally, it is preferred lens system to maintain the focus thereof in or on an that the condensed liquid be circulated in the conduit means in the vessel containing liquid to be distilled or elongated vention, collector. In another embodiment of the in the still is portable and is easily assembled and elsewhere to utilize heat contained in the condensed disassembled. Advantageously, the stills are operative water. The solution of salt (NaCl) dissolved in water 15 to distill seawater and brackish water and the portable abosrbs less infrared rays than water alone. Thus, where stills in particular may be used at sea, for example, on it is desired to reduce absorption of infrared rays in the lens fluid, a salt/water solution is preferably used as the lifeLenses boats, and in desert areas.

lens fluid. When desalinating sea water, the sea water is tion so thatmaythealso be combined according to the inven solar rays pass through the lenses seri preferably used as the lens fluid and preferably is also 20 ally to provide a sharper focus of the lens system. introduced preheated into the container holding the Apparatus according to the invention may be used to water to be distilled.

In the case of sea water, salt may be produced from Hydrogen, sodiumand electrolyze water salt recovered from distillation.

and chlorine may be recovered from the resulting concentrated brine and credit obtained the electrolysis. The recovery of these products further from the sale thereof to lower the overall cost of obtain 25 ing distilled water. Heat may also be recovered from the increases ditionally, the economic efficiency of the apparatus. Ad the hydrogen may be used as a non-polluting heated brine discharged from time to time from the system. According to the invention, combination con fuel or used with carbon monoxide to produce metha centrator systems including both fluid and Fresnel nol, or with nitrogen of the air to produce ammonia lenses can be advantageously used. In one such combi 30 fertilizer and urea.

and other nitrogen products such as nitric acid nation system, one set of fluid lens concentrators is inclined, for example, south at 15 with the horizontal, Still further in accordance with the invention, appa with the bottom plates of the lenses being cooled by ratus disclosed herein for producing electricity may be fluid circulating within the lenses whereby the vapor combined with hydroelectric means and apparatus dis condenses on the cooled bottom plates and flows there 35 closed herein may be combined with heat pumps and/or along into an adjacent vessel. Another set of Fresnel refrigeration apparatus and/or expansion means such as concentrators or fluid lenses are provided to receive the turbines, motors and engines.

sun's rays during hours of sunshine to primarily heat Still further in accordance with the invention, appa fluids having high boiling temperatures to over 200 C. ratus and methods having high efficiency and low cost in conduit means in the vessel containing liquid to be for concentrating, collecting and converting solar en distilled. The heat in the high boiling temperature fluids ergy are disclosed.

is stored and used primarily during periods without These and other aspects of the present invention will sunshine whereby evaporation and condensation of the be more apparent from the following description of the vapor on the cooled bottom plates of the fluid lenses preferred embodiments thereof when considered with continues during periods without sunshine. The Fresnel 45 the accompanying drawings.

lenses or a separate set of fluid lenses used to heat the BRIEF DESCRIPTION OF THE DRAWINGS high boiling temperature fluids to store heat are prefera bly provided with tracking means to follow the seasonal The present invention is illustrated by way of exam and preferably also the hourly location of the sun. Ac ple and not limitation in the figures of the accompany cording to one embodiment of the invention, the distil 50 ing drawings in which like numerals refer to like parts lation apparatus comprises a plurality of sets of fluid and in which:

lenses. One set of lenses has a lens plate separation at the FIG. it is a schematic perspective diagram showing a point of maximum separation of, for example, one inch system including an elongated fluid lens and an elon for minimum absorption of infrared rays and maximum gated collector, the lens being movable about a trans evaporation of the water to be distilled during periods 55 verse axis to track the sun's daytime location and the of sunshine. This set comprises smooth surface bottom lens and collector being interconnected and movable lens plates for condensing the vapor thereon which are about a longitudinal axis to track the sun's seasonal inclined to flow the condensate into a vessel located location;

below the edges thereof. The lens fluid in this set of FIGS. 2-4 are cross-section views showing different lenses will cool the bottom lens plates to provoke con 60 configurations of fluid lenses; densation thereon. Another set of lenses having a lens FIG. 5 is a perspective view showing a series of lon plate separation at the point of maximum separation for gitudinally juxtaposed fluid lenses and means for inter example of four inches is used for high absorption of communicating the enclosures of the respective lenses, infrared rays and contains a high boiling point (for ex this arrangement being utilizable to arrange a plurality ample about 200° C.) lens fluid which is communicated 65 of longitudinally juxtaposed lenses where a single lens is with a plurality of conduits located in the water to be shown;

distilled. This set of lenses and conduits is used primar FIG. 6 is a detail perspective view of FIG. 5 showing ily for storing heat as described hereinbefore to be used the lens frame;

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FIG. 7 is a perspective view of a lens system compris water in which the lens system comprises Fresnel and ing two separate plates for enclosing a lens fluid and a fluid lenses and has a plurality of foci located at differ frame for sealing the plates into a fluid-tight lens; ent depths in the water to be distilled, a Fresnel lens and FIG. 8 is a cross-section view of the lens and frame of collector being movable to track the seasonal location FIG. 7 taken along line 8-8; 5 of the sun and a set of lenses for preheating the incom FIG. 9 is a schematic perspective diagram showing ing water to be distilled;

another system in which panels of four fluid lenses each FIG. 2 is a schematic perspective diagram showing are arranged longitudinally and are focused on elon another system for distilling water in which the lens gated collectors, the panels and collectors being inter system comprises two fluid lenses and a plurality of connected and movable on a shaft rotated to track the 10 conduits to provide substantially continuous operation; sun's seasonal location and the lenses being movable and about a common transverse axis to track the sun's day FIG. 22 is a schematic perspective diagram showing time location as described in FIG. 1; two lenses through which the solar rays pass serially to FIG. i0 is a plan view of a planar, point-focusing, provide a sharper focus at a collector similar to the one Fresnel-type lens; 15 of FIG. 18, the lenses and collector being movable to FIG. 11 is a schematic perspective diagram showing track the sun.

another system comprising elongated, planar Fresnel DESCRIPTION OF THE PREFERRED lenses having a linear focus and collectors comprising EMBODIMENTS fluid-carrying conduits, the lenses and collectors being interconnected and movable as described for FIG. 1; 20 In FIG. ii is shown a solar energy collecting system FIG. 2 is a cross-section view of part of another comprising a refringent fluid lens concentrator and a collector comprising three fluid-carrying conduits in fluid-containing solar energy collector. System 20 com which the innermost conduit is enclosed by the interme prises an elongated fluid lens concentrator 22 and col diate conduit which is enclosed by the outermost con lector 24 in the form of elongated fluid-containing con duit; 25 duits. Elongated fluid lens 22 comprises solar energy FIG. 3 is a schematic perspective diagram of a com transmitting plates 26, 28, which are preferably separate posite system for distilling water comprising individual pieces mounted in frame 30 and spaced to enclose solar systems each including three elongated fluid lenses, two energy transmitting fluid 31. In the embodiment shown lenses being located on the same plane and the third at in FIG. 1, upper lens plate 26 is convex and lower plate an angle to the two, the foci of the lenses being located 30 28 is planar. The respective sides 32, 34 of lens plates 26, in a vessel containing the water to be distilled at differ 28 and the ends of the lens plates (not shown in FIG. 1) ent locations therein; are sealed to be fluid-tight in manners which will be FIG. 14 is a schematic cross-section diagram of a described hereinafter. Alternatively, means not shown composite system for distilling water comprising indi in FIG. for adding and removing or circulating fluid vidual systems, each comprising a single, elongated, 35 31 and air are provided in the sides and/or ends of the movable fluid lens to follow the seasonal location of the lens plates. Additionally, lenses may be longitudinally sun and a collector comprising a single fluid-carrying and transversely (radially) juxtaposed and will also be conduit, the individual systems being enclosed and the described hereinafter. In the embodiment shown in lenses and collectors being interconnected as described FIG. 1, collector 24 comprises an outer elongated con for FIG. 1; r duit 36 enclosing an inner elongated conduit 38, both FIG. 15 is a schematic perspective diagram of a por shown to be tubular in shape. Conduit 36 is placed in table, easily assembled and disassembled system having insulating container 40 and is surrounded by insulating a fluid lens for distilling water; material 42 except for a longitudinally extending open FIG. 56 is a schematic perspective diagram of an ing 44 located above conduit 36. Opening 44 is closed other portable easily assembled and disassembled sys 45 off by solar energy transmitting and heat insulating tem having Fresnel lenses for distilling water; plate 46. Plate 46 is suitably made of glass or plastic and FIG. 17 is a cross-section view of a photovoltaic cell the insulating material 42 is suitably a foam such as positioned in a fluid-carrying conduit to produce elec polyethylene foam. A sealing material such as, for ex tricity from solar energy with fluid circulating inside ample, silicone is provided between plate 46 and con and/or outside the conduit to remove heat; 50 tainer 40 to seal the container fluidtight. Collector 24 is FIG. 18 is a schematic perspective diagram showing located below lens 22 and the theoretical linear focus 48 a system comprising an elongated fluid lens focused on is located at or along the collector. The axis of the lens a collector having photovoltaic cells therein in which (and of the system) is oriented along the east-west direc the top of the collector is exposed to disperse heat pro tion.

duced thereat by the infrared rays, the fluid lens being 55 Frame 30 and lens 22 are supported by and pivotally movable and interconnected with the collector to track mounted in frame 50 to rotate about transverse axis 52 the seasonal and daily location of the sun as described in by members 53 and pivot joints (not shown). Cables 55 FIG. 1; are connected to opposed sides of frame 30 adjacent FIG. 19 is a schematic cross-section view of a lens sides 32, 34 of the lens, at opposed ends of the lens (only system including a central fluid lens and adjacent Fres 60 one of which is shown) and wound about rollers or nel lenses each having engravings thereon angled to pulleys 58 to run the cables in a common direction provide the Fresnel lenses with the same focus as that of towards drive means (not shown). Movement of cables the fluid lens, the common focus being located at an 55 in the direction of the arrows pivots lens 22 about elongated collector which is interconnected with the axis 52 moving plate 26 towards the west. Movement of lenses, both the lenses and collector being movable to 65 cables connected to the other end of frame 30 (not track the sun's position; shown) pivots lens 22 about axis 52 moving plate 26 FIG. 20 is a schematic perspective diagram showing towards the east. Thus, lens 22 is rotatable in the east a system for substantially continuous distillation of west direction to track the sun's hourly movement.

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Lens 22 and collector 24 are also rotatable in the north C., for example, 200 C., the precise temperature at south direction about longitudinal axis 60 to track the tained depending on many factors such as the flow rate sun's seasonal movement. Frame 50, in which is of fluids 54, 56, the diameters of conduits 36, 38, sun mounted lens 22, is pivotally mounted adjacent the ends intensity and position, insulation, heat exchange rates, of the lens to supporting frame 62 by members 64 (only etc. Fluid 54 is selected to have a boiling point which is one of which is shown) and pivot joints (not shown). less than the boiling point of fluid 56, preferably at least Rigidly interconnected to frame 50 is collector 24 by 50 C. less than the boiling point of fluid 56, and prefera members 66. Frame 50 and collector 24 are rotatable as bly in the temperature range of from about -60 C. to a unit about axis 64 thereby maintaining the relative about 100 C. Such a fluid is suitably water. It is also orientation between the collector and lens unchanged. O preferred that fluid 54 have a low latent heat of vapori Cables 68 (only one of which is shown) are connected zation, for example, from about 20 calories per kilogram to one side of the collector to pivot the lens and collec to about 270 calories per kilogram, and such fluids may tor towards the northerly direction and cables 70 (only comprise by way of example and not limitation refriger one of which is shown) are connected to the other side ants, solvents, hydrocarbons, alcohol, etc. of the collector to pivot the lens and collector towards 15 In operation, solar energy is concentrated in fluid 56 the southerly direction to a position such as the one (chosen to be lubricating oil) within conduit 38 and shown in broken lines. Cables 68 and 70 are also wound raises the temperature of the oil to about 200° C. Since around pulleys 58 to run the cables in a common direc the focus to lens 22 is theoretically linear, fluid 56 will tion towards drive means (not shown). The lens and be continually heated as it traverses the linear focus. collector are rotatable over a total angle of about 47 20 Fluid 54 (chosen to be water) surrounds the oil and degrees during the year in the north-south direction. conduit 38, and is heated primarily by the oil primarily The drive means may comprise, for example, electric through conduction. Both fluids, oil and water, are motors activated and controlled by sensors such as circulated at predetermined rates to obtain desired tem phototransistors or by electric timers. Automatic, semi peratures and may be used for different heat applica automatic or manual means may be used to track the 25 tions. For example, the water may be heated to about sun's location in addition to the one illustrated in FIG. 70’ C. to 80 C. or more and used for space and hot 1 and described above. One system uses an electric water heating. The water may be heated to lower tem motor whose shaft is turned by a small angle whenever peratures and used, for example, in swimming pools. the direct or focused sunlight hits a photocell or ther The higher temperature oil may be used for applications mo-couple. Hydraulic systems may also be used to 30 requiring higher temperatures including industrial ap move the lenses and collectors. Other systems use a plications or may be used merely to heat the water. timer or a weight and pulley device. Movement of the Since the temperature of fluid 56 increases as it tra sun affects the electric output of the photocell to con verses the lens focus, fluids at many different tempera trol the motor or the motor is controlled by the timer to tures are realizable by providing taps for fluid outlet turn the shaft in small angular increments, or the weight 35 and/or inlet at different points along the focus. Fluid 54 and pulley device turns the shaft. As mentioned, such may be evaporated and the vapor or superheated vapor complete systems for moving the lenses and sensing the used to produce mechanical power in expansion means sun's position are known and are not shown. Parts of such as motors, turbines and engines which, in turn, systems used for tracking the sun's position are shown may generate electricity. Preferably, a closed system in the drawings. While daily or hourly tracking is pre 40 (not shown) is employed in which the condensed fluid is ferred to enhance solar energy collection, it is not re returned to collector 24. In such applications, fluids quired since the collector and lens are generally ori such as refrigerants, solvents, hydrocarbons, alcohol, ented in the east-west direction. By interconnecting and etc., and the like may constitute fluid 54. moving the lens and collector, the lens focus is always As mentioned hereinbefore, a serious drawback of maintained at the collector regardless of season. The 45 solar energy systems in general and known systems in above-described tracking arrangement substantially particular relates to the storage of energy during peri increases solar energy collection since the system is ods in which there is no sunshine or the intensity thereof always oriented in directions directly facing the sun, is low, as for example during the night or during periods seasonally and preferably hourly. Means 71 are pro of cloudy weather. Heat is stored for use in those peri vided for sensing the location of the sun and for moving 50 ods in fluid 56 which is heated during normal system the lines and the lens and collector via the cables 55 and operation to a temperature which is at least about 50° C. 70, respectively. higher than the temperature of fluid 54. Therefore, even As mentioned hereinbefore, the collector is located at when fluid 56 is not being heated by solar energy or the theoretical focus 48 of the lens 22 and in the embodi being heated at a reduced rate, it stores heat and will ment of FIG. 1, conduits 36 and 38 are solar energy 55 continue to supply heat to fluid 54 due to the tempera transmitting, the theoretical focus 48 being located ture difference between the two fluids. Preferably, the within the inner conduit 38. Conduits 36 and 38 contain circulation of fluid 56 is stopped for those periods. Fluid heat-carrying fluids 54 and 56, respectively. Since the 56 continues to transfer heat to fluid 54 until the differ concentration of the solar energy will be greatest in the ence in the temperature of the two fluids is relatively fluid within the conduit at which the lens theoretical small. The time that fluid 56 will transfer and/or store focus is located, i.e., in fluid 56 within conduit 38, fluid heat depends upon the initial temperature of fluid 56, 56 may be heated to a relatively high temperature and is the difference in temperatures between the fluids, the therefore chosen to have a relatively high boiling point, volumes of the fluid, the characteristics (specific heat, for example, from about 150° C. to about 350° C. Such boiling point, latent heat, etc.) of the fluids, the use to fluids may comprise by way of example and not limita 65 which fluid 54 is put, etc.

tion lubricating oils, glycerine, mineral oils, paraffin The fluid 31 in lens 22 may be communicated with oils, etc. Thus, during periods of sunshine, fluid 56 is one of the conduits in the collector 24 to remove heat heated to a temperature which may be in excess of 100 from the lens fluid, thereby maintaining it at a suitable 17 temperature while utilizing heat from the solar energy tubular, and the lenses and lens systerns may be other absorbed by the lens fluid to, for example, preheat the than that shown in FIG. . .

fluids circulating in conduits 36 and/or 38. Referring now to FIGS. 2-8, the fluid lenses may In FIG. ii, collector 24 was shown to comprise tubu have configurations other than that shown in F.G. i. In lar conduits 36, 38. However, the conduits need not be 5 F.G. 2 is shown planar-convex lens 22 comprising cur tubular and in some instances other configurations are vilinear upper plate 26 and spaced planar lower plate 28 preferred such as for example, rectangular. A rectangul enclosing solar energy transmitting fluid 3i. The plates lar configuration may be desirable when the theoretical may be economically made of glass or plastic and are focus has deviations. Providing a rectangular shape will joined at sides 32, 34 in a fluid-tight manner as by weid allow movement of focus 48 while still maintaining it at O ing or gluing. Alternatively, lens 25 may be extruded conduit 36. Focus 48 can be on the surface of conduit with sides 32, 34 integrally joined. The ends of the 36, and in such a case, the surface of conduit 36 need not lenses may similarly be glued, welded or extruded. FiG. be solar energy transmitting and is preferably darkened. 3 shows a bi-convex lens 78 comprising spaced curvilin It is to be understood that the systems shown in the ear plates 26. Lens 78 is formed as described for lens 22. remaining figures and described hereinafter are longitu 15 Lens 80 shown in FIG. 4 comprises curvilinear upper dinally oriented in an east-west direction and faced plate 82, spaced planar lower plate 84 and side walls 86. towards the sun. It is to be further understood that the Lens 80 is economically formed from a bulb of glass or elongated lenses or lens system and the elongated col plastic as by blowing as, for example, in the manufac lectors and conduits thereof are arranged substantially 20 ture of glass or plastic bottles. The lenses shown in along parallel longitudinally axes. It is to be still further FIGS. 2-4 when used in solar energy systems are sup understood that it is preferred that the concentrators ported by suitable frames and structural members. For example, lens 88 is supported by frame 38 shown in and collectors are movable and that means may be pro FIGS. 5 and 6. As there shown, a plurality of lenses 86 vided for moving them to track the seasonal and prefer are longitudinally juxtaposed at ends 98 and supported ably the hourly location of the sun. Movement of the 25 by longitudinal support lenses, however, may not be required where the lens port stringers 94. The stringers 92 and transverse sup focal length is short such that displacement of the focal frame by, for example, adhesives. Asbeshown lenses may secured to the in FGS. 5 line will be small from season to season and remain and 6, the theoretical focus 96 of the lenses is at and within the periphery of the inside conduit 38 of the along collector. Manual, automatic or seni-automatic drive 30 are collector 98. Means in the form of openings 169 means for effecting tracking movement of systems and provided to add and remove fluid 32 and/or air and /or lenses on a seasonal or hourly basis are known. tubes the openings may be communicated by, for example, While only part of a single lens is shown in FIG. 1, it is openings102 to provide for circulation of the fluid. The to be understood that many lenses may be longitudi ple, may be provided in other locations, for exam nally and transversely located. as shown in FGS. 2-5 and referenced by a 60. As 35 mentioned hereinbefore, the plates forming the lenses

Conduits 36 and 38 in FIG. may both include may be integrally extruded or blown or may comprise opaque heat conducting surfaces and the lower part of separate plates joined as by welding. Referring now to the surface of either conduit 36 and/or conduit 38 is preferably darked by black paint or the respective con FIGS. 7 and 8, upper cirvilinear plate 26 and lower planar plate 28 are separate pieces and are joined in a duit or conduits are preferably provided at the lower 40 fluid-tight manner by means of frame C4. Frame 104. half of the surfaces thereof with back metallic sheets to comprises two longitudinal grooves 106, 68. The prevent transmission of solar energy and to enhance upper groove 156 is curviliner and sized to accommo heat absorption from the solar energy.

Additionally, plate 46 provides agreenhouse effect in date upper curvilinear plate 26 while the lower groove is liner and sized to accommodate planar plate 23. The the collectors, and container 40 is preferably made of 45 edges of the respective separate plates are inserted into insulating material to further reduce heat losses. The the respective grooves along with sealing material il. reduction in heat loss is especially important during The ends of the plates are similarly joined. The material periods of no or reduced sunshine. However, as will be 110 may comprise a gasket or similar flexible piece described more fully hereinafter, plate 46 may be elimi and/or deformable material such as silicone to form nated when it is not desired to retain heat at the lens 50 fluid-tight joints. Thus, the lenses according to the in focus such as when photovoltaic cells are located vention in which two independent plates are joined or thereat. It is preferred that the theoretical focus of the the lenses are extruded or blown, are relatively easy to lenses be located at the inner fluid to further reduce heat manufacture and are relatively inexpensive. The re losses since the outer fluid will act as an insulator. The quired radius of curvature of the curvilinear convex solar energy transmitting tubes in FIG. 1 are preferably 55 plate and the focal distance to the collector from the made of colorless and transparent glass or plastic and lens will depend on the width of the plates, the maxi the tubes which need not transmit solar energy there mum distance between the plates and the refractory through are preferably metal, preferably steel, cooper index of the fluid between the plates, and fluids with or aluminum, and all are preferably darkened at their higher refractory indices shorten the required radius lower surfaces. 60 and focal distance.

The area of the collector surfaces may be much Depending on the lens fluid used and the distance smaller than the area of the concentrators and may be between the lens plates, a percentage of the infrared only from about 1% to about 10% of the area of the rays in the wave length range of about 0.7 to about 4 conventional flatplate collector, thus reducing the heat microns impinging on the lens will not pass through the losses accordingly. As less material is required in the 65 lens. Some of the infrared rays will be absorbed directly collector, the cost will be reduced. by the fluid and heat it. Some of the infrared rays will be The collector systems may comprise a number of absorbed by the lens plates which will be heated and in conduits other than two and configurations other than turn partly heat the fluid. Part of the solar energy will 18 be reflected by each plate, part of the reflected solar tioned for heating and/or production of additional elec energy being reflected towards the inside of each plate tricity. Thus, the invention provides a highly economic into the lens to also be partly absorbed by the lens fluid. combination of simultaneously generating heat and Little of the liminous rays in the wave length range of electricity.

about 0.25 to about 0.7 microns will be absorbed in a 5 Referring now to FIG. 9, system 70 is made up of transparent and colorless lens fluid and transparent and panels 71 of fluid lenses 22. Each panel comprises four colorless lens piates. For certain applications, it is desir fluid lenses 22 arranged transversely and longitudinally able that the absorption of infrared rays be minimized, adjacent one another. The panels are supported and for example, where it is desired to produce as much heat rotatable to track the sun seasonally and hourly. Frame as possible at the lens focus. In other applications, it may 10 50 is supported on shafts 64 which are rotatably con be desirable to heat the lens fluid and/or provide as little nected to frame 62 at opposite ends of the frame by heat as possible at the lens focus while transmitting as means such as bearings. One end of one of the shafts 64 much as possible of the luminous rays such as, for exam is connected to drive means (not shown) such as an ple, when photovoltaic cells are located at the lens electric motor. Lenses 22 and frame 50 are rotatable focus. In the former case, the distance between the lens 15 about longitudinal axis 60 by rotating shaft 64 to track plates is minimized, for example, to about 1 inch at the the sun seasonally. Frame 30 is pivotally connected to point of maximum separation of the lens plates, and the frame 50 by members 52 and is movable with lenses 22 lens fluid is chosen to absorb at ambient temperature a about the common transverse axis 53 to track the sun's minimal amount of infrared rays and preferably has an position as described for FIG. 1.

index of refraction of at least 1.35. Fluids such as hydro 20 In FIG. 10 is shown a plane refringent element 126 carbons, mineral oils, solvents, solutions such as salt comprising a rigid frame 128 surrounding a sheet or water, etc. are transparent, colorless and absorb sub plate of plastic or glass material 130 in which are stantially less infrared radiation than water. When used, formed by impressions or molding concentric, closely the fluids are preferably chosen to be non-corrosive to spaced rings or microplasms 132 whose pitch, for exam glass and plastic and to have a suitable boiling tempera 25 ple, corresponds to about 3 to about 4 microprisms per ture. Some fluids having a high index of refracton and millimeter. The plane refringent element 126 acts like a low absorption of infrared rays such as trichloroethy plane Fresnel lens. Solar energy striking the refringent lene and toluene are corrosive to plastics such as acrylic element 126 is concentrated by the microprisms into a plastics. When using such corrosive fluids, the lens theoretical point focus (not shown). Refrngent element plates exposed to the fluid are covered by sheets such as 30 126 may be positioned longitudinally juxtaposed as the Teflon or coatings of epoxy such as Luctie RD which fluid lenses in FIG. 5 and/or transversely juxtaposed as are not corroded by the lens fluid. In the latter case, the the lenses in FIGS. 9 and 13. The system may be ar distance between the lens plates is maximized, for exam ranged so that the point foci of lenses 126 are located ple to about 4 inches at the point of maximum separation within or at the surface or conduits 36 and 38, the series of the lens plates, and the fluid is chosen to absorb at 35 of discrete point foci along a length forming in effect, a ambient temperature a maximum amount of the infrared linear focus composed of discrete point foci. rays while still being transparent and colorless. The System 130 of FIG. 11 is shown employing elongated degree of absorption of infrared rays is also dependent refringent elements 32 having longitudinal micro upon the material used for the lenses. For example, for prisms 134 acting as longitudinal Fresnel lenses. The low absorption, waterwhite glass with about 1.5% ab lenses 132 and collectors 24 are arranged so that the sorption or plastic with a similarly low absorption may linear focus of a column of lenses is located at a respec be used with a lens fluid such as a salt water solution. tive collector as described for FIG. 9. The lenses and Where a high degree of absorption of infrared rays is collectors are interconnected and movable as the sys desired, for example, in electricity-producing applica tems shown in FIGS. 1 and 9.

tions wherein the solar energy is focused on photovol 45 FIG. 12 shows an arrangement for three conduits in taic cells, glass and plastic lenses with lens fluids having which the inner conduit 139 is enclosed by intermediate an infrared absorption of, for example, 20% may be conduit 141 which in turn is enclosed by outer conduit used. It is preferred that water be used in the latter case 36. Providing three conduits permits use of three differ where it is desired to absorb infrared radiation. In cer ent fluids, allows for use of the fluids at varying temper tain locations, an antifreeze product is added to the 50 atures for many different applications and allows for a water to prevent freezing. If water is used in the collec larger displacement of the focal line. tor, an antifreeze product is also added to the collector The present invention may be utilized for many en water. With water used as the lens fluid and the larger ergy applications as described hereinbefore and may distance (for example about 4 inches) separating the lens also be advantageously used to distill or otherwise treat plates, there will be an increased absorption of the infra 55 water by evaporation and condensation thereof. Typi red rays by the lens fluid and a corresponding increase cally, the water is seawater or brackish water and is to in heating of the lens fluid. The heat in the lens fluid can be desalinated, or water or a liquid containing minerals be recuperated in heat exchangers and used for heating or other substances, or water such as industrial waste and/or preheating the collector fluids as described here water or polluted water which is to be purified and inbefore. The heat may also be used to heat water for 60 distilled. The refringent concentrators and collectors domestic use or for other uses, or to heat buildings, or to are arranged in systems operative to distill water, pref produce electricity by superheating low boiling temper erably recovering the heat of condensation and prefera ature fluids and expanding the vapor in expansion bly recovering heat in the condensed water and dis means such as turbines or engines. Since the lens fluid charged brine as described hereinafter. Embodiments of permits most of the luminous rays to be transmitted 65 such systems are shown in FIGS. 13, 14, 15, 16, 20 and therethrough, electrical generation by the photovoltaic 2.

cells will be essentially undiminished while the lens The system shown in FIG. 13 comprises a plurality of fluid is being heated and the heat being used as men sub-systems 162, each employing a three lens arrange 19 ment 64. Each lens system 64 is supported above an the respective channels. The water 170 to be distilled elongated, central, channel 166 and parallel, elongated, may be held bvetween predetermined heights by a float side channels 168 such that the central part of the lens system comprising float 178 and relays 80 and 82. system is above the central channels and the outer lon Movement of the float activates respective relays to gitudinal edges of the outer two lenses are above the start and stop a pump or motor valve (not shown). A side channels. Each lens is inclined and the bottom lens similar arrangement may be used in side channels 568 or plates 28 are planar. The water 170 to be distilled is a gravitational drain arrangement may be employed to filled in the central channel to a predetermined height. maintain the height of distilled water in the side chan Within channel 166 are located the elongated foci F of nels between predetermined heights. The respective the lenses, preferably at different locations and different O channels are communicated to provide approximately heights, the different heights corresponding to different equal levels in each of the respective channels. Advan water depths in channel 166. In FIG. 13, lens fluid 35 is tageously, the channels are made of concrete or asbes advantageously salt water. The solution of salt (NaCl) tos cement and are preferably insulated on the outer dissolved in water absorbs less infrared rays than water sides. Means other than the lens itself may be used to alone. Thus, where it is desired to reduce absorption of 15 condense the vapor such as substantially smooth prefer infrared rays in the lens fluid, a salt/water solution is ably planar plates located below the lenses 64. In such preferably used as the lens fluid. When desalinating sea a case, the lens fluid may not recover substantially all of water, the sea water is preferably used as the lens fluid the latent heat unless the plate is proximate thereto. and preferably is also introduced preheated into the Alternatively, means associated with the plate may be container holding the water to be distilled. Valving is 20 used to recover the latent heat. provided in the conduits to control draining and to The system shown in FIG. 3 is substantially en regulate circulation of the fluids. In operation, the water closed by the channel panels to reduce heat loss. The 70 to be distilled is heated due to the solar energy recovery of the latent heat of the condensing vapor by concentrated at foci F and the water 70 is vaporized. the lens fluid and the recovery of the sensible heat in the The vapor strikes the lower plates 28, is condensed 25 condensed water assist in providing a continuous opera thereon and flows therealong to be discharged at or tion system since heat losses are reduced. Additionally, dropped from the edges thereof into side channel 68. as mentioned, by removing from the lens fluid the heat The interiors of the fluid lenses are communicated with of condensation recovered by it, for example, by circu the interior of channels 166 by conduits 77 (only one lating it in channels 66, the lens fluid will be cooled, in set of which are shown) as well as being inter-com 30 turn cooling the lower lens plate and assisting in con municated. Heat exchange means 79 may be provided densing any vapor impinging thereon. As described inside channel 66, particularly for transferring heat hereinbefore, the lens fluid will be heated by direct and from the condensed water in channel 168 to the water in indirect absorption of infrared radiation and by heating channel 66. The water in the fluid lenses is circulated of the lens plates, and this heat may also be recovered through the lenses and channels. In this way, the heat 35 from the lens fluid. The heat recovered from the lens released by condensation of the vapor is transmitted fluid and condensed water may be used to preheat through plates 28 to the water in the lenses and the heat water to be distilled before entering channel 166 or to absorbed by the water in the lens from the condensing preheat and heat the water to be distilled in channel 166 vapor is returned to the system in the channels. Thus, by heat exchange means. The efficiency of the system the water to be distilled may be heated or preheated. can be further increased by recovering the heat con The lenses 22 are arranged so that the foci F remain tained in the brine discharged from channel E65 from within channels 66 regardless of the seasonal and day time to time. The heat which is recovered from the time location of the sun, the foci moving along the paths condensing vapor, the condensed water, the brine and indicated in channel 166 by the broken lines. Thus, the the lens fluid can be used for other purposes such as foci will not be displaced outside channels 66 and it is 45 producing electricity by superheating and expanding therefore not necessary to provide means to move the fluids having low boiling temperatures and low heats of lenses to follow the location of the sun. Heat in the vaporization. The water distillation systems described distilled water may also be utilized to preheat or heat hereinafter operate in similar mannewr and description the water to be distilled. The distilled water may only thereof will therefore be more limited. be a few degrees less than the vapor temperature. The 50 In F.G. 14, an expandable material forms the side recovered heat may also be used for other purposes and panels 226, 208 of each compartment 210 of the system. the lens fluid and/or condensate can be circulated Advantageously, the material is of plastic. Opposed through heat-exchanging means to remove the heat ends 212, 214 of adjacent side walls 208,206 are secured therefrom. This is significant because the latent heat of to respective sides of lenses 22. Adjacent interior side about 540 calories per gram required to vaporize the 55 walls are of one piece and are advantageously formed as water 70 and the sensible heat released by condensa a single sheet 226. Sheet 256 is wound partially about tion of the vapor are substantially recuperated from the the circumference of tubular members 28 which ex condensate. This heat is substantially returned to the tend along longitudinal axes parallel to those of the system by the circulated water in the lenses upon which channels 22, 222. The tubular members are secured by the vapor condenses. This latent heat and the sensible means (not shown) to maintain sheets 26 as side walls heat are substantial and would otherwise be lost. This 208, 206 as shown. The lower sides 25 of lenses 22 results in much higher efficiency of the system com terminate above channels 222. The evaporation and pared with solar stills where channels filled with water condensation of the water proceeds as described herein to be treated are covered with only glass or plastic before. In addition to the system being enclosed con plates or sheets which receive the solar rays. Circulat 65 densed water flows down side panel 208; and side panels ing the water in the lenses also cools the lower lens 266, 208, when cooled by the outside environment, will plates 28 thereby assisting condensation thereon. Con provide additional condensation of vapor which will duits 175 and 176 are provided for filling and emptying flow down panel 206 as well. The system remains en 20 closed upon movement of the lens as follows. If the and emptying. Distillation of water 170 by heating of lenses are rotated counterclockwise, interior side panels the fluid in conduit 312, advantageously water, and 206 move downwardly and interior side panels 208 evaporation of the water, condensation of the vapor on move upwardly about tubular members 218. The exte the lens and collecting of the condensate proceed as rior side panels 206a and 208a are secured to the sides of 5 described hereinbefore. Expandable side panels 320 respective channels and are made of an expandable may be provided to enclose the system and allow for material. Lenses 22 and collector 188 are communicated movement of lens 282 as described hereinbefore and by conduits 219 and valves 221 (only one set of which is may be used to form collecting bags as shown in FIG. shown). The water in the fluid lenses may thereby be 14. Means are provided to indicate the water levels in circulated in collector 188. In this way, the heat relesed 10 the vessels 306, 314 such as vertical transparent glass or by condensation of the vapor is transmitted through the plastic tubes 322,324 located outside side panels 320 and plate 28 to the water in the lenses and the heat absorbed connected by tubing with the bottoms of the vessels. by the water in the lens from the condensing vapor is In FIG. 16 is shown another embodiment of a porta returned to the system. Thus, the water to be distilled ble water distillation system 330 which is easily assem may be heated or preheated and fluids in the collector 15 bled and disassembled. System 330 comprises planar may be heated or preheated. Heat in the distilled water Fresnel Lenses 126 of the type shown in FIG. 10 having may also be utilized to preheat or heat the water to be concentric microprisms causing the solar energy to be distilled or fluids in the collector by means of conduits concentrated at point foci. A longitudinal Fresnel lens 223 (only one set of which is shown) and heat exchange or lenses may also be used. Lenses 126 are longitudi means, and circulation of fluid therethrough or else 20 nally and transversely juxtaposed to form a composite where. The distilled water may only be a few degrees lens assembly of six Fresnel lenses which is inclined less than the vapor temperature. The recovered heat with respect to the horizontal, six being chosen for may also be used for other purposes and the lens fluid purposes of illustration. The lenses are formed into an and/or condensate can be circulated through heat assembly by, for example, securing them as by adhe exchanging mens to remove the heat therefrom. Of 25 sives to a solar energy transmitting glass or plastic plate course, whether conduits 219 or conduits 223 or both 332 which, in the case of plastic, may be folded along are used will depend upon the lens fluid used, the fluid flexible partition lines 334. Each Fresnel lens may be used in collector 188 and the arrangement of heat ex about 9 inches by about 7 inches and are presently avail change means. able at a cost of about $0.40 each. The point foci of the Referring now to FIG. 15, a portable water distilla 30 lenses are located in the water to be distilled in flexible tion system 280 is shown comprising single vessel 306 container or bag 336 made of plastic or other pliable holding the water 170 to be distilled. The system is material. Flexible container or bag 338 made of plastic easily assembled and disassembled. Lens 282 is made of or other flexible material located below and extending flexible solar energy transmitting material such as clear beyond container 336 is used to collect condensate from plastic and forms an enclosure 286 when inflated by a 35 plate 332. The lens assembly and containers are Sup fluid, advantageously water, which is introduced and ported by support assembly 340 comprising pairs of legs removed and/or circulated by means including inlet 288 342, 344, frame 346 and platform 348. The legs are piv and outlet 290. Air is also removed and fluid introduced otably connected to frame 346 as described for FIG. 15 through said means. Also, fluid and Fresnel (circular or to adjust the angle of incline of the lens assembly to longitudinal microprisms) lenses as described hereinbe 40 follow the seasonal location of the sun. The containers fore may be used. Lens 280 is supported by frame 292 of or bags have side panels 350,352 which extend upwards metal or other suitable material which comprises upper to plates 332 to form an enclosed system as described frame members 294 and side support members 296. The hereinbefore. An opening is provided in side panel 352 upper ends 297 of the side support members 296 are at the lower side of plate 332 to allow the condensate to pivotably connected to the upper frame members 294 as 45 drop into the collector bag 338. Means such as transpar by bolts 298 such that each of the side support members ent tubes 322,324 connected to the bottom the contain is pivotable about the bolts in the directions indicated ers are used to indicate water levels therein as described by the arrows. Means such as indentations 300 are pro for FIG. 15. The lens assembly, support assembly and vided in platform 302 to secure in the lower ends 304 of containers are easily assembled and disassembled. The the side members in selected positions. Alternatively, a 50 foci located in the water to be distilled in container 336 platform is not used and ends 304 may be secured in the heat the water and cause it to evaporate, condensing on ground or otherwise. Pivoting of side members 296 the bottom of planar plates 332. The condensate moves adjusts angle A at which lens 282 is inclined. The elon along plates 332 and falls into container 338. Depending gated vessel 306 advantageously collapsible and made upon location, production of distilled water will be of lightweight plastic is hung from frame members 294 55 about 1 pound per hour for a system as shown in FIG. below the central part of elongated lens 282 by cables or 15 having a lens surface area of 10 square feet (about 1 rope 308. Hinges 310 are provided to secure the cables square meter). This production of distilled water is to the vessel. Adjustment of angle A and movement of without recovering the latent heat of condensation. cables 308 permit the lens focus to be positioned in Production of distilled water could be about eight times vessel 306 during different seasons. A collecting vessel 60 larger if the latentheat of condensation is recovered. As 314 is located below vessel 306 and below the lower mentioned hereinbefore, portable systems can be used at inclined end 316 of the lens 282. Vessel 314 advanta sea or in desert areas. - geously collapsible and made of lightweight plastic is According to another aspect of the invention, the also hung from upper frame members by cables or ropes concentrated solar energy is used to generate electricity 308 and hinges 310. Vessel 314 is inclined preferably 65 by means of photovoltaic cells. Referring to FIG. 17, along the longitudinal direction to assist in draining photovoltaic cells 398 made of silicon or cadmium sul treated water therefrom by means such as valve 317 in fide or other materials are disposed in the interior of outlet 318. Port 320 is provided in vessel 306 for filling inner fluid-carrying conduit 400 shown advantageously 21 to be of rectangular cross-section. The theoretical focus 402 of the lens is at the cells and preferably on the outer surface thereof. The cells may be juxtaposed in series and also in parallel in the theoretical focus 402 in linear or spaced if the theoretical focus 402 is a point focus. 5 The concentrated luminous rays are converted to elec tricity by the cells while the heat absorbed by the cells from the infrared rays is removed by the circulating fluid 404 and also by the fluid 406 circulating within the outer conduit 408. The removal of heat can be con 10 trolled by the size of the conduits 402, 426 and by the volume and rate at which the fluid is circulated. Prefer ably fluid 44 is substantially electrically non-conduc tive such as air or other gases and liquids. Means (not shown) are provided for connecting the cells in parallel 5 or series and for removing the generated electricity. If fluid 404 is electrically conducting, means (not shown) are provided for electrically insulating the cells and the means for interconnecting the cells and for removing the generated electricity. Conduit 402 has at least its 20 upper surface made of transparent material if the theo retical focus 42 is linear or transparent apertures may be provided above the cells if the theoretical focus 402 is at a point. The upper part of outer conduit 408 is also transparent. The details of inner and outer conduits 25 have been described hereinbefore.

As mentioned hereinbefore, concentrating the uni nous energy of the sun with a concentration of up to about 100 permits electricity to be generated at up to about 100 times more power while the increased heat 30 energy is dissipated and removed by the fluids in the conduits. As described hereinbefore, the amount of heat produced at the photovoltaic cells may be reduced by absorption of infrared radiation in a fluid lens. This will increase the efficiency of the cells while reducing the 35 heat dissipating requirements of the collector. The heat absorbed in the lens fluid may be recovered as described hereinbefore. Electricity may be generated in conjunc tion with other uses of solar energy. For example, using a dual fluid carrying collector, photovoltaic cells may be inserted therein as just described and electricity gen erated while the heat energy is being used to heat a structure. Additionally, the electricity generated may be used to electrolyze water and/or salt to produce hydrogen, sodium and chlorine. The hydrogen may be used with carbon monoxide to manufacture methanoi or with nitrogen of the air to produce amonia fertilizer and other nitrogen products such as nitric acid and area. Such electrolysis may be used together with the distilla tion apparatus of the invention. Still further in accor SO dance with the invention, apparatus generating electric ity using solar energy may be combined with hydro electric means having water storage means. Such a combination provides for the production of electricity at night, during periods of reduced sunshine, or during 55 peak demand periods by the hydroelectric means while the Solar energy systein produces electricity during periods of sunshine. The solar energy system may be provided as a floating installation on the reservoir and thereby not require additional land. 60 As mentioned hereinbefore, it may be advantageous in some instances to eliminate the plate 46 of FIG. a used to produce a greenhouse effect in the collector. Referring to FIG. 18, system 410 is shown comprising fluid lens 22. Collector 414 does not include a plate such 65 as plate 46 of FIG. a so that heat from the infrared rays is not retained in the collector. Additionally, photovol taic cells 398 and transparent conduits 36, 38 are only partially located in container 412 of collector 424 to further disperse heat produced by infrared rays focused at the cells. Location of conduits and cells only partially in insulating material 42 of container 412 provides a wide-angle exposure of the photovoltaic cells to the surface of the fluid-lens. Other details of collector 414 are similar to those described herinbefore. Elimination of plate 46 and its associated sealant and the reduction in insulation used reduce the cost of the collector while dispersing heat produced by the infrared rays. The lens fluid and the distance between the lens plates are chosen to maximize absorption of the infrared rays in the lens. The lens and collector are novable as described for

Fluid lenses having upper and lower plates are gener aily of large size and consequently have long focal lengths which are generally longer than the width of the plates. Longitudinal Fresnel lenses having longitu dinal microprisms are generally of smaller size and have shorter focal lengths. Since the longitudinal micro prisms decrease in height toward the center of the lens, the lens width is limited. Also, the width of the glass or plastic sheets used for the Fresnel lenses is limited. This can be used to great advantage. For exampie, plate $5 or conduit 426 may be eliminated but the greenihouse ef. fect retained by reducing the distance between the lenses and the collector in an enclosed system. FIG. 19 shows a combination of a central fluid eas 20:2 with four adjacent Fresnel lenses 202 to 264, each having engravings anged to direct the solar rays to a common elongated focus 203 which is also the focus of the central fluid lens. The lens systein Inay ca intercon nected with collector 265 and be made movable to track the position of the sun as described hereinabove. The lens systein may comprise two Fresnel lens instead of four. Also, the lenses may be arranged longitudinally and transversely as shown in FiG. 9 to increase substan tially the concentration of solar energy, particularly for use in the production of electricity with photovoltaic cells.

Fluid lenses are larger than Fresnel lenses and are less efficient absorbing and reflecting more solar energy than Fresnel lenses. Thus, a system comprised entirely of fluid lenses is generally less efficient than a systern having only Fresnel lenses or at least one Fresnel lens combined with at least one fluid lens. Further in accor dance with the invention, systeins are provided which include fluid and Fresne lenses. Such systems can be used to great advantage in distilling water where fluid lenses increase overall efficiency by recovering the heat of vaporization of the water being distilled. Referring to FIG. 20, such a systein 459 is shown. System 45 coin prises fluid lens 22 and Fresnel lenses 132A and 32B. Each lens has a different foucs within channel 66 con taining the water 170 to be distilled. Channel 166 is trough-shaped to provide varying depths of water and the different foci are located at different depths. A nar row Fresnel concentrator 32A is positioned over the area in channel 66 in which water to be distilled is introduced which is reference by 45i. Lens i32A is used to preheat water introduced into channel ió5, for exam ple to 40 C. As a result, almost no condensation occurs at such location. Highly efficient Fresnel lens 132B is inclined at a steep angle with the horizontal facing north, and is focused inside the inner conduit in collec tor 172 which is of the two conduit type. Collector 272 and Fresnel lens 132B are connected and the lens is supported as described for FEG. S so both are novable 22 to track the seasonal and hourly location of the sun. tors is provided to increase the overall collector surface Preferably, flexible sheets 452, 453 are provided and area in channel 166. The inner conduits 38 are inserted attached on one side to the support for the Fresnel lens in outer conduits 36. Another fluid such as water flows 132A and on the other side at the support structure for in outer conduits 36 about conduit 38. The fluid circu the fluid lens 22. The inner conduit 38 carries a high lated in conduit 36 will be heated to, for example, 90° C. boiling point fluid which is capable of being heated to a to heat the water 170 contained in the vessel 166. The high temperature of, for example, 200 C. This, in turn, flow of the high temperature fluid in conduits 36 is heats the lower boiling point fluid in the outer conduit stopped during hours without sunshine and the fluid to, for example, 80 C. Because of its steep angle, be with high temperature is stored in the inner conduits 38 cause it is not cooled by a fluid as is a fluid lens, little 10 and continues to heat the fluid in the outer conduits 36. vapor condenses on lens 132B. Fluid lens 22, having a The outer conduits 36 will in turn heat the water to be lower efficiency than lens 132B, is inclined at a slight distilled during hours without sun. Lenses 22A with angle with the horizontal facing south of, for example, cooled bottom plates 28 will condense the water vapor 15 which is sufficient to cause condensate to flow along so produced and also during hours without sunshine, lower plate 28 and be discharged into channel 168. Lens 5 and discharge the condensate into the channel 168. 22 is focused directly in channel 166 so that its focus During hours with sunshine, lenses 22A provide heat will be in water 170 regardless of the sun's seasonal and for vaporization of the water to be distilled. In the sys daytime location. A substantial amount of the vapor tem described above, and shown in FIG. 21, the lenses will impinge on lens 22 because of its location. The need not be made movable to track the sun since the foci Fresnel/fluid lens combination shown in FIG. 20 has 20 of the lenses will always be in the vessel containing the the following advantages. Using a plurality of lenses, water to be distilled. As mentioned hereinabove, prefer and collectors and foci at varying water depths permits ably a salt/water solution and preferably sea water is heating the water to different temperatures at different used as the lens fluid, and in the case of distillation of depths to set up currents which assist in overall water seawater, the seawater from the lens being introduced heating and evaporation, thereby increasing system 25 into the vessel preheated.

efficiency. Employing Fresnel lenses to heat the water Solar energy systems may, according to the inven while providing a fluid lens on which the vapor con tion, be combined with heat pumps (either with a con denses permits recuperation of the heat of vaporization pressor or an absorption system). The combination by the lens fluid while still employing the more efficient could be used in air conditioning systems, refrigeration movable Fresnel lenses. The fluid lens is not movable 30 systems and/or as a heat storage system wherein the since a suitable angle of inclination must be maintained heat pump provides heat when there is no or reduced for the condensate to flow along the bottom plate of the sunshine. A heat pump uses either air or preferably lens. The focus of lens 22 will always be in channel 166 water as a source of heat or heat obtained from solar regardless of season. Using a two conduit collector 172 energy collected by the fluid or fluids in the collectors at the focus of the efficient Fresnel lens and including a 35 described hereinabove to vaporize the circulating re high boiling point fluid permits raising the temperature frigerant. If water is used, a large reservoir is generally of that fluid to about 200° C. whereby heat may be required as the outflowing water is cooled to a low stored as described hereinbefore and used during the temperature and may freeze if the reservoir is a small night. Locating the focus of lens 22 directly in the chan one. The heat obtainable from a heat pump depends on nel heats up the water quickly and provides heat to the the difference in absolute temperature between the heat water 170 during periods of sunshine. During periods source used to vaporize the refrigerant and the con without sunshine (and even during periods of sunshine densed refrigerant. The heat obtained by the heat pump when heat is removed from the lens fluid), the lens fluid can be from two to five times higher than the power is cool and will provoke greater condensation of vapor. required in the compressor for the refrigerant. The heat This combination permits continuous operation, the 45 pump may be used to provide additional heat during focus of lens 22 directly in the channel providing evapo hours without sunshine. The combination of the solar ration of water during periods of sunshine and collector energy system with a hydroelectric plant having a 172 in which fluids are heated to 200° C. in the inner water reservoir can be used to great advantage with a conduit and 80 C. in the outer conduit storing heat and heat pump, wherein the heat is obtained by the heat providing for evaporation of water during periods with 50 pump from the water of the reservoir of the hydroelec and without sunshine assisted by a lower lens plate 28 tric plant.

cooled by the lens fluid. W Lenses may also be combined so that the solar rays Another embodiment for distilling water similar to pass serially through them. Such an arrangement pro the apparatus shown in FIG. 20 is shown in FIG. 21. vides a sharper focus at the collector and is particularly However, in FIG. 21, two sets of double plate fluid 55 useful where the lens is focused on photovoltaic cells. lenses are provided. One set of lenses 22A is inclined FIG. 22 shows fluid lens 22 as described hereinabove south at, for example, 15 with the horizontal and has a superposed over Fresnel lens 132 as described herein smaller distance between plates of, for example 1 inch at above. Collector 414A is similar to collector 414, photo the point of maximum separation. Such plates will have voltaic cells 398 being disposed therein as in FIG. 18. sloped, cooled bottom plates to allow the vapor to con However, conduits 36, 38 are not enclosed to provide dense on such plates and to flow toward and be dis the greenhouse heating effect. In FIG. 22, the conduits charged into channel 168. Another set of lenses 22B are disposed entirely in insulating container 412A. contains circulating lens fluid having preferably a boil However, the wide trough-like opening 413 in the con ing temperature over 200 C. and high infrared ray tainer which is not closed off reduces greenhouse effect absorption characteristics. This fluid is circulated from 65 heating. Other collectors as described hereinbefore may the lens system into the inner conduits 38 of a series of be used where a greenhouse effect is desired. Both preferably metallic interconnected collectors 172, lenses are preferably movable to track the normal loca 172A, 172B, 172C. A plurality of interconnected collec tion of the sun, Lens 22 is supported as described for

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FIG. 1 while lens 132 is supported below lens 22 in a seasonally track the sun and are highly efficient while manner similar to that in which collector 414A is sup the fixed fluid lenses tilted at 15 can recover the latent ported. Additionally, either lens may be superposed heat of vaporization and can enhance condensation. over the other and two Fresnel or two fluid lenses may The foci of the fixed fluid lenses remain in the channel be used. holding the water to be distilled regardless of the sea CONCLUSION sonal position of the sun.

Further according to the invention water containing

Prominent aspects and advantages of the invention salt or other substances is distilled using solar energy may be summarized as follows. 8 collection and concentration according to the invention A lens concentration system is combined with a con 10 and recovering a large part of the latent heat of vapori duit collector system in which the surface area of the zation (about 540 calories per gram) released by the concentrating system exposed to the sun is from about condensing vapor and the sensible heat. This is accom 10 to about 100 times larger than the surface area of the plished by using the fluid circulating in the lens system collecting system through which the energy is concen to recover the latent heat and circulating the fluid in the trated. As a result, heat losses are reduced substantially 15 conduit in the water to be distilled or elsewhere thereby since the collector has an area of, for example, only heating or preheating the water to be distilled or other from about 1% to about 10% of conventional flat plate wise utilizing the recovered heat while cooling the lens collector systems. Thus, the efficiency over conven tional flat plate systems is in the order of about 50% fluid The and lower plate to enhance condensation thereon.

recovered heat may also be used to heat fluids in higher. This reduction in surface area reduces corre 20 the conduit. Additionally, the distilled water may be spondingly the material requirements per unit of surface circulated through the conduits area exposed to the sun and the investment cost is also ing the water to be distilled orinelsewhere the channel contain reduced correspondingly by about one-half. Addition additional heat and this heat may also be usedtotorecover heat or ally, higher efficiency results in a lower cost for energy preheat the water to be distilled. Still further heat may produced. 25 be recovered from the heated brine discharged from

In providing more efficient systems according to the time to time from the system by circulating it as de invention, fluid lenses could be used to absorb infrared scribed hereinabove for the lens fluid and condensate. radiation thereby reducing the heat produced at the lens Preferably a solution of salt in water or sea water is used focus. This is extremely useful where photoelectric cells as the lens fluid are located at the lens focus. In such fluid lenses, the 30 preheated form.and can be introduced for distillation in Thus, extremely high efficiencies are distance between the lens plates is maximized and the attainable with the present lens fluid chosen for maximum absorption of infrared concentrated brine may alsoinvention. be The salt from the recovered and sold or rays by the fluid lens. The heat absorbed by the lens electrolyzed. Distillation according to the invention is fluid may be recovered and put to use. In other applica at low cost. The invention provides for portable dis tions, the lens fluid and distance between the lens plates mountable distillation units which could be used to may be chosen to minimize absorption of the infrared rays by the fluid lens. In applications where a green distill sea water in life boats or brackish water in arid house effect is desirous to reduce heat losses, collectors desert areas thereby possibly saving lives. The inven according to the invention are provided with at least tion also contemplates a floating installation at sea on a one conduit which is disposed in a collector container large ship such as a previously mothballed aircraft car whose top is closed by a transparent plate and sealant rier located in a warm, sunny climate whereby sea therefor, or with a plurality of conduits with the outer water can efficiently and inexpensively be distilled. conduit being transparent and containing a gaseous fluid While specific applications of the invention have been enclosing at least one inner conduit and acting to pro described, many other uses of the collected solar energy vide a greenhouse effect for the inner conduit. The 45 are possible. For example, the salt by-product of desali conduits in the collector container of the latter type nation may be collected and sold to reduce the overall may be exposed to the lens systems over a wide angle. operating cost of the system. Additionally, the salt may The outer transparent conduit and the transparent plate be separated into sodium and chlorine by electrolysis by providing the greenhouse effect may be eliminated electricity preferably generated by the solar energy where it is desired to disperse the heat from the infrared SO collecting system. In this respect, water can be sepa rays at the collector while still exposing the conduit at rated into hydrogen and oxygen also be electrolysis, which the lens system is focused to a large lens surface from electricity preferably generated by solar energy, area. Thus, efficiencies of the solar energy systems ac the hydrogen of which in turn be used with carbon cording to the invention can be increased while lower monoxide in the manufacture of liquid methanol which ing cost by eliminating the transparent plate and sealant 55 is easily transported and may be used as fuel for automo for the collector entirely or replacing it with a transpar biles, airplanes, etc. The system described hereinbefore ent conduit. Efficiency can further be increased and could be combined with hydroelectric means and/or cost lowered by combining in a single system the use of with known heat pumps. (compression and absorption) Fresnel and fluid lenses, each of which provide individ to further utilize the collected solar energy in combina ual advantages to the overall system. Such a composite 60 tion with the heat provided by the heat pumps, particu system is particularly useful for distilling water and may larly for refrigeration systems. In addition to providing include a plurality of collectors which are preferably energy for heating, the systems according to the inven located at different depths in the water to be distilled tion could be used for air conditioning and, as just men and include one collector which comprises a conduit tioned, in refrigeration systems. Also the multi-conduit carrying a high boiling point fluid capable of being collectors and fluids are capable of providing tempera heated to about 200 C. Thus, the collectors and lenses tures of about 70 C. to about 80 C. for heating rooms are used to provide efficient continuous operation. For and for heating water, and at higher temperatures, for example, the Fresnel lenses may be made movable to example, about 180 C. to about 200 C., for heat stor 24 age applications and to produce electricity, and may be characterized by elongated conduit means comprising a combined with expansion motors. plurality of conduits each containing a fluid therein, The apparatus according to the invention has been said conduits being arranged such that at least two flu described primarily using schematic diagrams. Accord ids in the conduits are contiguous, and fluid lens means ingly, certain details not essential to an understanding of 5 for concentrating the solar energy along an elongated the invention have been omitted. For example, the ma focus at said collector means located substantially in or terials and support structure comprising the apparatus on and substantially along at least one of the conduits, according to the invention not described in detail will said fluid lens means comprising a solar-energy trans be known to those skilled in the respective arts. The mitting lens fluid and opposed solar energy transmitting sizes of the parts of the apparatus described hereinbe 10 plates enclosing said lens fluid, said lens plates being fore will vary depending on the use to which the appa spaced and said lens fluid being chosen to absorb a ratus is put. minimum amount of infrared solar energy, said lens As shown in FIG. 9, many fluid lens may be trans fluid being chosen from the group consisting of sol versely and longitudinally juxtaposed to form compos vents, hydrocarbons, and salt and water solutions, said ite systems from individual systems or vary large sys 15 lens fluid having an index of refraction of greater than tems. The Fresnel-type lenses may have similar length about 1.35, and said lens means further selectively com and width dimensions and may be similarly employed in prising means for protecting lens plates otherwise cor composite or large systems. Portable distillation units roded by said lens fluid.

may be used, for example, as mentioned hereinbefore, in 5. Apparatus for collecting and concentrating solar lifeboats to distill sea water or in desert areas to distill 20 energy comprising in combination collector means brackish water and thereby possibly save lives. Portable characterized by elongated conduit means comprising a units according to the invention could produce, for plurality of conduits each containing a fluid therein, example, one pound of distilled water for every square said conduits being arranged such that at least two flu meter (about 10 square feet) of lens concentrator area ids in the conduits are contiguous, and fluid lens means exposed to the sun's rays, and this without recapturing 25 for concentrating the solar energy along an elongated the heat of condensation. The production of distilled focus at said collector means located substantially in or water, however, will be about eight times as great if the on and substantially along at least one of the conduits, heat of condensation is recovered. said fluid lens means comprising a solar-energy trans It is pointed out that the heat obtained from the sun mitting lens fluid and opposed solar energy transmitting using the energy systems according to the invention 30 plates enclosing said lens fluid, said lens plates being may be lower in cost than heat energy obtained from spaced and said lens fluid being chosen to absorb a fuels which may thus be replaced. Heat storage pro minimum amount of infrared solar energy, said lens vided by systems according to the invention is a feature fluid being chosen from the group consisting of solvents which also makes these systems competitive with fuels. and hydrocarbons including trichlorethylene and tolu The distillation systems according to the invention are 35 ene, said lens means further selectively comprising capable of providing distilled water at low cost and means for protecting lens plates otherwise corroded by therefore are important where clean water is scarce. said lens fluid.

The advantages of the present invention, as well as 6. The apparatus of claim 5, wherein said lens plates certain changes and modifications of the disclosed em are spaced by about one inch at the point of maximum bodiments thereof, will be readily apparent to those 40 separation.

skilled in the art. It is the applicant's intention to cover 7. The apparatus of claim 5, wherein the material used by his claims all those changes and modifications which for said lens plates is chosen from the group consisting could be made to the embodiments of the invention of glass and plastic, and wherein said lens plates are herein chosen for the purposes of the disclosure without chosen to absorb not greater than about 1.5% of the departing from the spirit and scope of the invention. 45 infrared solar energy.

Protection by Letters Patent of this invention in all its 8. The apparatus of claim 5, wherein said lens means aspects as the same are set forth in the appended claims further comprises at least one Fresnel lens for concen is sought to the broadest extent that the prior art allows. trating solar energy at said collector means. What is claimed is: 9. The apparatus of claim 5 and further comprising 1. A lens system for concentrating solar energy com 50 means for moving and orienting said lens means about at prising at least three lenses, a first of said lenses being an least one axis to track at least one of the sun's seasonal elongated lens located centrally of the others of said and daytime locations, said means including means for lenses and having an elongated focus, the others of said sensing the location of the sun.

lenses being elongated Fresnel-type lenses having longi 10. Apparatus for concentrating and collecting solar tudinal microprisims, and elongated foci, said Fresnel 55 energy comprising a lens system which includes at least type lenses being positioned and said microprisims three lenses, a first of said lenses being an elongated lens being arranged so that the foci of said Fresnel-type located centrally of the others of said lenses and having lenses are substantially coextensive with said focus of an elongated focus, the others of said lenses being elon said lens, and means for interconnecting said lenses for gated Fresnel-type lenses having longitudinal micro tracking movement, whereby the foci of said lenses 60 prisms and elongated foci, said Fresnel-type lenses remain substantially coextensive during tracking of the being positioned and said microprisms being arranged S. so that the foci of said Fresnel lenses are substantially 2. The lens system of claim 1, wherein said elongated coextensive with said focus of said first lens, elongated lens is a fluid lens. collector means having an elongated axis, the collector 3. The lens system of claim 1, wherein said elongated means being spaced from said lenses and positioned lens is a Fresnel lens. substantially along the foci of said lenses with its axis 4. Apparatus for collecting and concentrating solar substantially parallel to the foci of said lenses, and energy comprising in combination collector means means for interconnecting said lenses for tracking 25 movement thereof, whereby the foci of said lenses re said second frame means and said third frame means main substantially coextensive during tracking of the being pivotably connected independently of said collec S. tor means by said second pivot means for pivoting about ii. The apparatus of claim 10 and including connect the transverse axis.

ing means for rigidly connecting said interconnected 5 17. The apparatus of claim 16, wherein said legis lenses and said collector means and supporting means means and collector means are disposed with their elon for pivotably supporting said connecting means for gated axis substantially in the east-west direction, pivoting of said interconnected lenses and collector whereby pivoting of said lens means and collector means about the elongated axis of said first lens, means about the elongated axis of said lens means is whereby the foci of said lenses is maintained substan 10 operative to track the sun's seasonal location and pivot tially along said collector means during tracking of the ing of said lens means about the transverse axis indepen S. dently of said collector means is operative to track the 12. The apparatus of claim 11, wherein said elongated sun's daily location.

lens is a fluid lens.

13. The apparatus of claimila, wherein said elongated 15 pivot The means apparatus of claim 17, wherein said second are positioned intermediate opposed ends lens is a Fresnel lens. of said lens means.

14. Apparatus for concentrating and collecting solar 19. Apparatus for concentrating and collecting solar energy comprising in combination elongated collector energy comprising in combination elongated collector means and elongated lens means for concentrating solar means and elongated lens means for concentrating solar energy at said collector means, connecting means for 20 energy at said collector means, connecting means for rigidly interconnecting said lens means and collector rigidly interconnecting said lens means and collector means in a spaced relationship wherein elongated axes means in a spaced relationship wherein elongated axes of said lens means and collector means are in substan tially parallel planes, and supporting means for pivota of said lens means and collector means are in substan tially parallel planes, and supporting means for pivota bly supporting said lens means and said collector means 25 bly supporting said lens means and said collector means interconnected thereto for pivoting about the elongated interconnected axis of said lens means, whereby the interconnected lens axis of said lens thereto for pivoting about the elongated means and collector means may be pivoted to track the means and collector means may the means, whereby interconnected lens be pivoted to track the sun in a first direction, said supporting means pivotably sun in a first direction, said supporting means pivotably supporting said lens means for pivoting independently 30 supporting said lens means for pivoting about an axis of said collector means about an axis transverse to the elongated axis of said lens means, whereby the lens transverse to the elongated axis of said lens means, means may be pivoted independently of the collector in whereby the lens means may be pivoted to track the sun means to track the sun in a second direction which is a second direction which is transverse to the first transverse to the first direction. 35 direction, said supporting means comprising first frame 5. The apparatus of claim 14, wherein said support means and second frame means, said first frame means ing means comprises first frame means and second comprising first pivot means for pivotably supporting frame means, said first frame means comprising first said second frame means for pivoting of said second pivot means for pivotably supporting said second frame frame means about the elongated axis of said lens means, means along the elongated axis of said lens means, said 40 said connecting means inter-connecting said collector connecting means interconnecting said collector means means to said second frame means for pivotable move to said second frame means for pivotable movement ment therewith, said second frame means comprising therewith. second pivot means positioned intermediate opposed 16. The apparatus of claim 15, wherein said support ends of said lens means for pivotably supporting said ing means comprises third frame means and second 45 lens means for pivoting about the transverse axis. pivot means for pivotably supporting said lens means,

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United states patent and trademark office

Certificate of correction

PATENT NO. 4, 2l0, li2l Page l of 2

NVENTOR(S) : Virgil Stark

It is certified that error appears in the above-identified patent and that said Letters Patent is hereby corrected as shown below:

Column 5, line l6, change "abosrbs" to --absorbs--. Column 8, line 50, change "fluidtight" to --fluid-tight--. Column ll, line 20 change "longitudinally" to --longitudinal--. Column ll line 58, change "cooper" to --copper--.

Column l2, line 38, change "cirvilinear" to -- curvilinear--. Column l2, line 44, change "liner" to --linear--.

Column l3, line 3l change "Luctie" to --Lucite--.

Column l4, line 29, change "Refrngent" to --Refringent--. Column 14, line 67, after "system" insert --l60--. Column l6, line 2 change "bvetween" to --between.--.

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United states patent and trademark office

Certificate of correction

PATENT NO. : 4, 210, 12 Page 2 of 2

INVENTOR(S) : Virgil Stark it is certified that error appears in the above-identified patent and that said Letters Patent is hereby Corrected as shown below:

Column 16, line 48 change: "mannewir" to --manner--. Column l7, line 10, change "relesed" to --released.--. Column l7, line 25, change "mens" to --means--.

Column l8, line l6, change "Lenses" to --lenses--. Column 20 line 35, change "lens" (second occurrence) to

Column 20 line 60, change "reference" to --referenced--. Column 25, line l5, change "vary" to --very--.

Column 25 line 59, between "said" and "lens" insert --first--. eigned and sealed this

Sixth Day of January 1981

Seal

Attest:

Sidney a. diamond

Attesting Officer Commissioner of Patents and Trademarks